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Heat Stress and Carbon Monoxide Heat Stress and Carbon Monoxide Exposure DuringExposure During

C-130 Vehicle TransportationC-130 Vehicle Transportation

Dor A, Pokroy R M.D., Zilberberg M MHA,Barenboim E M.D. MHA, Goldstein L M.D. MHA

The IAF Surgeon General HQ, ISRAEL

INTRODUCTIONINTRODUCTION The C-130 is often used for military vehicle airlift

Loading vehicles with running engines (“hot”)

The hot climate

Direct convection heating of the aircraft

heat stress to the aircrew

Heat stress effects performance

Driving on and off C-130 : A potential contamination by exhaust gases .

Carbon Monoxide (CO)

Fatigue

Headache

Nausea CO and high altitude flights

OBJECTIVESOBJECTIVES

Investigating heat stress and CO exposure during C-130 vehicle transportation,

Ensuring the safety of C-130 aircrew.

METHODSMETHODSMETHODSMETHODS

Data - 2 night (18:00–08:00) + 2 day (08:00 –18:00) C-130 summer flights.

2-3 vehicles with working gasoline engines per flight.

The aircraft air conditioning was active, except day time takeoffs.

METHODSMETHODS

The cabin Heat Stress index (wet bulb globe temperature- WBGT) and CO levels before (control) and after vehicle loading were compared

2 -and 3-vehicle transportations

Day and night transportations

were compared

Dry bulb temperature and cabin heat stress index - measured at 10-min intervals

Runway ambient temperature - before takeoff and after landing

METHODSMETHODS

Carbon Monoxide- 30 sec intervals

using an inorganic gas monitor Compared with the recommended exposure limits of the ACGIH

)American Conference of Governmental Industrial Hygienists(

METHODSMETHODS

RESULTSRESULTS

Heat Stress Index vehicle transportation

Heat Stress Index > recommended limit (28°C)

Until vehicle unloading

Activated cooling system

Heat Stress higher in all flights (transport and control) during the day than the night flights (p< 0.0001).

During day flights, 2 vehicle transportation flight had a significantly lower mean WBGT than the 3 vehicle transportation (27.8°C vs. 35.8°C, p=0.0001)

While no difference was recorded between the 2 or 3 vehicle transport during the night flights (20.2°C vs. 20.5°C, p=0.46)

Cabin Heat Stress index > TLV in 74% of the measurements during daytime flights

Heat Stress directly related to flight duration Heat Stress directly related to flight duration in day and night transport flightsin day and night transport flights

(P=0.001 & P= 0.001)(P=0.001 & P= 0.001)

RESULTSRESULTS

Fig Fig 11:: Heat stress during day flights Heat stress during day flights

Note the increase in WBGT after vehicle loading, which continued to increase for the full flight duration of 140 minutes

Fig 2:Fig 2: Heat stress during night flights Heat stress during night flights

Note the increase in WBGT after vehicle loading

RESULTSRESULTS

DISCUSSIONDISCUSSION

Solar heating of C-130 body on the runaway in day flights before loading corresponds with other studies

“Hot” Vehicle loading caused sharp Heat Stress index increase

above the accepted ACGIH limit

3 -vehicle night flight: CO just above the TLV

3-vehicle day flight: CO approached Action Level

Warning level -recommend preventive actions

Other studies - correlation between increased CO levels the number of engines acting simultaneously

DISCUSSIONDISCUSSION

CO TLV is based on an 8-h work shift .

Our longest transport duration - only 160 min

CO exposure is well below the TLV-time weighted average formula not considered hazardous

Major drawback- CO levels in ambient airCO levels in ambient air

Vs blood CO monitoring

DISCUSSIONDISCUSSION

C-130 crews are exposed to Heat Stress and CO during “hot” vehicle transportation

The air conditioning system of the early C-130 models provides inadequate cooling under conditions of severe heat stress

SUMMARYSUMMARY

Recommendation - increasing the natural ventilation of the plane before takeoff by opening the front and the rear door during ground stand-by

Recommendation - using industrial fans on the runway during loading if the ambient temperature exceeds 28°C.

SUMMARYSUMMARY

Further investigation:

Aircrew blood CO monitoring + ventilation recommendations

SUMMARYSUMMARY

QuestionsQuestions??? ???